With the popularity of straw bale gardening, composting, and mulching, it might seem that decorative Halloween bales could be an amazing garden resource. But you may wonder if this autumn decor is contaminated with weed seeds, plant diseases, or herbicides.
Before you start spreading straw all over your garden, let’s dig into the potential risks and benefits of using Halloween bales in the garden and how to ensure you can use them safely without damaging your soil or plants.
The Short Answer
Make sure your bales are noxious weed seed-free to avoid weed problems.
You can safely use Halloween straw bales in the garden as chicken bedding plant protection, pathway mulch, and a carbon-rich compost input. The least risky way to reuse them is to spread the straw between pathways for mud control and weed suppression. If you have backyard laying hens, this can be a perfect addition to their coop for warmth and cleanliness through winter.
But before you throw it into your garden, check that you have certified noxious weed seed-free straw rather than hay. Adding hay or straw that hasn’t been certified to be free of noxious weed seeds to your garden could result in a disastrous mess of weed growth. If unsure, only spread your decorative bales as mulch on your garden’s borders or use it in your chicken coop.
I would not recommend adding these bales to your edible garden beds if you prefer to use organic practices. Unless you know the farmer who grew it or it was certified organic when you bought it, there’s a good chance it was sprayed with herbicides, which could leach into your soil and harm your crops. For the safest mulch option in organic edible beds, purchase premium straw grown without long-lasting herbicides.
The Long Answer
Decorative bales may contain herbicides if not acquired from a safe, known source.
Due to the unknown sourcing of most decorative bales, I hesitate to recommend them for edible garden beds. Do you know the source of your straw? Are you fairly certain that it is weed-free and herbicide-free? Then go ahead and mulch away! But if you purchased the bales strictly for decoration and have no idea what is in them, avoid applying them to your edible beds.
You can still repurpose straw in the garden by using it as a pathway or border mulch, which significantly cuts down on mud during the winter. Scrap bales are also great to add to your chicken coop for bedding. The carbon-rich material buffers the high-nitrogen manure to create rich organic matter over time.
Straw also makes a great compost input because the high heat of a healthy compost pile will likely kill off any weed seeds or pathogens and reduce the risk of herbicide contamination in your garden.
But before you do anything with your Halloween bales, identify if they are hay or straw.
Hay vs. Straw
Hay is made of dried legumes or grasses, whereas straw is the dried stalk of grains like wheat or barley.
Never spread a bale without knowing what’s in it! While both come in rectangular or circular bales, straw is made of grain stalks, while hay is made of dried legumes or grasses with seed heads. Straw uses include animal bedding, mulch, and autumn decor. Hay is animal feed.
|Contains grass leaves and can have visible seedheads||Dry hollow stalks and stems (little to no seeds)|
|Grass, alfalfa, timothy, rye, or forage legumes||Byproduct of wheat, oat, or other cereal crop harvest|
|Grown for livestock feed||Grown for animal bedding|
|Light green color||Golden-brown color|
|Slightly sweet smell||Little to no smell|
|Might grow a grass lawn in your garden||Sometimes safe for garden use as mulch or a compost input|
Confusing hay and straw in your garden could have detrimental effects! Hay is a legume or grass with its seedheads intact or partially intact. Spreading hay in your garden could inadvertently cause grassy growth instead of a vegetable bed. Straw, on the other hand, is the stalk of a grain crop.
When a farmer harvests a field, most hay varieties will have green leaves and nutrient-rich seedheads for animal feed. This is baled up into hay and used for livestock feed when pasture access is limited. Hay often includes blends of legumes like clover, alfalfa, or timothy and may include some weeds from the same field (although some farmers provide hay that has been certified free of noxious weeds).
Straw comes from primarily dried cereal crop stems and stalks, with very few or little seeds. Since it’s usually from a cereal grain like wheat, oat, or barley, straw may contain a few remaining grain seeds, although most seedheads will be harvested during a first pass of the field for flour or feed. The remaining stalks are what become the straw we use for mulching.
Conventional herbicides used on cereal grains may linger in the straw.
While they may seem like an innocent garden input, these decorative bales come with a few notable risks, particularly for vegetable growers.
Your bales may have…
Straw is typically seed-free and better for gardening purposes, but that doesn’t mean the occasional wheat or barley stalk won’t pop up in your beds. Always check that you have straw, not hay. If it has a golden-brown color and the stalks appear hollow, it is probably straw. If it is light green with leaves and seeds, it is probably hay. Avoid spreading hay bales in your garden if you’re uncertain what seeds it might contain!
Many hay and straw producers now offer the option of a certified noxious weed seed-free blend. These certified blends do not mean that they entirely lack seeds, however. It means that the field has had noxious weeds removed, preventing their seeds from ending up in the final product. This can be done with conventional means or organic ones, but in both cases it means that the weeds themselves are prevented from maturing in the field. There may still be seeds in there, but they’ll be seeds from the plants that make up the hay itself, so for instance, a timothy hay may have timothy hay seed in it.
Modern-day cereal grains may be heavily sprayed with herbicides, some of which may pose major risks. I’ve known farmers who accidentally brought in local compost made from contaminated straw, and their entire summer greenhouse was devastated by herbicide damage. Symptoms include twisted stems, distorted leaves, yellowing, plant death, and complete yield loss. To make matters worse, many herbicides are persistent, meaning they can stay in the soil for months or years.
While there are organic options out there if you prefer, the best bet for conventional straw is to source straw from a reliable and safe producer who is willing to disclose what they use on their grain stalks. Typically, loose straw meant for chicken coop bedding or other small livestock use is less likely to have heavy herbicide use. If you know the grower who produces your straw, you can also ensure you’re using materials that are garden-safe.
You never know what fungal pathogens or rots reside within a tightly bound bale. Rotten straw bales can harbor many disease-causing organisms you don’t want to spread to your garden. Be sure to break open the bale and examine it for any signs of mildew, black mold, rot, or foul smells, all of which can happen in the somewhat anaerobic interior of a straw bale. If the straw appears rotten, compost it; it’s already past the point of being usable as a clean mulch but can still provide valuable organic matter once it breaks down fully.
Use straw as weed-suppressing mulch and to prevent erosion during rainy seasons.
Decorative straw bales may have some modern-day risks, but that should not discount the incredible functionality of straw in general. This is a historically phenomenal gardening input. Straw is a carbon-rich, biodegradable organic material that can serve many functions in the garden.
Strawberries have “straw” in their name for a reason; they naturally grow in layers of decomposed grass and tree debris. Similarly, straw bales create a nice pillow for many crops. You can spread them into an amazing, soil-warming mulch for perennial and annual plants. A thick layer of straw mulch is incredible at reducing the evaporation of moisture from the soil during hot weather, helping to save water and reduce the frequency of watering. In addition, straw can significantly improve garden cleanliness during the rainy winter months by preventing weeds and reducing erosion.
The potential garden benefits of Halloween bales include:
If you keep backyard laying hens, chicken bedding is likely the best use for your leftover biodegradable Halloween decor. Spread straw around your chicken coop to keep the ladies warm and dry during winter. The straw will also buffer the moisture and nitrogen content of manure so the coop doesn’t become a muddy mess. If you don’t feel like spreading the straw, simply loosen the bale, and the hens will scratch it out for you while removing any remaining seeds they find.
Layers of straw protect fragile plant root zones from the frost heaves of frigid winters. When mulch is thickly spread over the root zone of overwintering plants, it acts like a cozy blanket, moderating the soil temperature and improving the frost resilience of tender plants. I particularly love shredded straw for overwintering brassicas and herbaceous perennials, and I’ll use leftover holiday straw bales for mulching ornamental trees and shrubs.
As long as your straw bales are weed-free, a 1-2” thick layer of mulch can dramatically reduce your weed pressure. The thick interwoven nature of straw pieces creates a weed-smothering mat that prevents weed seeds from accessing sunlight.
Organic matter is the fancy word for dead stuff. Any plant that was once living (like wheat or oat straw!) will add organic matter to your soil, creating a richer soil environment over time. Keep in mind that thicker straw stalks take longer to decompose, whereas finer straw will degrade more quickly to nurture soil texture.
Straw is an excellent compost input for maintaining the proper ratio of carbon-rich to nitrogen-rich materials. If you have a lot of kitchen scraps, garden debris, or animal manure, large amounts of straw or other carbon-rich material are needed to balance out the nitrogen-rich wastes to create healthy compost. Without enough carbonaceous material, your compost pile can quickly turn to stinky green mush. Add shredded straw liberally to home compost bins to fuel beneficial microbial growth and keep your compost smelling nice.
If you are confident in the quality of your straw, use it as mulch for your perennial and ornamental beds or incorporate it into your home compost pile! But if you’re wary about the state of your Halloween straw bales, give them to the chickens or spread them in your pathways. It just isn’t worth the risk of contaminating your garden with grass seeds or herbicides. For your edible garden beds, opt for a premium straw mulch like GardenStraw, which is what Kevin uses on the Epic Homestead!